More than 1,800 members of Unite who are employed by Arriva are to vote on whether to strike in a dispute over pay.
Bus workers across the North West are preparing to ballot for industrial action from Monday, June 20.
The voting will close on Monday, July 4, and industrial action could take place later than month.
READ MORE: Strike action to be voted on by 1,800 Arriva bus employees in the North West in pay dispute
Unite said the dispute is a result of Arriva offering the workers a "pitifully low pay increase" that involved a "maximum no strings pay increase" of 3% or a 6% increase which "includes reductions in sick pay and loss of Saturday enhanced pay".
It added that both offers are "far below" the current real inflation rate (RPI) of 11.1%.
Unite general secretary Sharon Graham said: "Arriva needs to get serious and make our members a realistic pay offer. Arriva can full afford to pay our members a fair rate of pay but it is choosing not to do so to boost its profits.
"Unite is totally committed to defending our members jobs, pay and conditions and will be giving our members at Arriva its complete support until this dispute is resolved."
The depots involved in the dispute are: Birkenhead, Bolton, Bootle, Liverpool, Macclesfield, Manchester, Runcorn, Southport, Speke, St Helens and Winsford.
Unite regional officer Dave Roberts added: "Strike action would result in considerable disruption for passengers throughout the North West but this dispute is entirely of Arriva’s own making.
"Despite extensive negotiations it has failed to make an offer which is anywhere close to our members’ expectations.
"Even at this late stage strike action could still be avoided if Arriva returns to the negotiating table and makes a realistic pay offer."
An Arriva spokesman said: "We are fully committed to reaching an agreement with Unite for our North West staff and talks are ongoing."
